Homosexual that is trying to loot your booty. Has connotations of the theft of booty in a coercive manner from the unwilling.

"Why don't you relax and free yourself from all those blocks that society has imposed upon you, fun can be found in the most incredible places..." - "Aaaargh, butt pirates!!! To your fighting positions matees we are under attaaaack!"

a man who is really really gay and likes to scream
HHHHHYYYYYYAAAAAARRRRRGGGGG every time he has ass sex, rapes someone in the ass, or grabs and or looks at a males ass. a tell tale sign of a butt pirate is if you hear a guy say "HHHYYYAAARRRGGG your booty shivers my timbers" to another guy.